Abstract: Provided are: a SOUR-resistant heavy-wall steel plate having excellent low-temperature toughness and post-heat treatment characteristics; and a method for manufacturing the same. The SOUR-resistant heavy-wall steel plate of the present invention comprises: in terms of weight %, 0.02-0.06% of C; 0.5% or less of Si (excluding 0%); 0.8-2.0% of Mn; 0.03% or less of P; 0.003% or less of S; 0.06% or less of Al; 0.01% or less of N; 0.005-0.1% of Nb; 0.005-0.05% of Ti; 0.0005-0.005% of Ca; one or more selected from 0.05-0.5% of Ni, 0.05-0.5% of Cr, 0.02-0.4% of Mo, and 0.005-0.1% of V; and the remainder Fe and unavoidable impurities, wherein the heavy-wall steel plate satisfies relational expressions 1-3, and has a percent ductile fracture of 85% or more in the drop weight tear test (DWTT) at ?20° C.

Abstract: A heating system for drill steel pipe billet includes a feedback device configured to control distances d1 and d2 of three flamethrowers, a propulsion device, a positioning device, a heating device, a temperature measuring device and a conveying device. Heating temperature of the flamethrowers is controlled by an oxygen distribution box and a gas distribution box. A heating method for the drill steel pipe billet is also provided, in which a rolling forming method of gradient flame heating is adopted to control density of the rolled pieces and avoid internal defects of the drill steel caused by the same deformation of the traditional uniformly heated pipe billets. A radial temperature of the drill steel pipe billet is accurately controlled through the feedback device. Only one set of flamethrowers corresponding to drill steel pipe billets of different dimensions is required, and other devices are universal components, which will not be replaced.

Abstract: A bushing assembly for a track assembly includes a first end element, a second end element, and a central element positioned between the first end element and the second end element. The central element may be interference fit or positioned between the first end element and the second end element, and the central element may include a greater hardness than the first and second end elements. The first end element, the second end element, and the central element form a bushing with a longitudinal opening extending longitudinally through the bushing.

Abstract: A method can be employed to produce a rack for a steering gear. The rack may include a toothed portion with a toothing, and a shaft portion with a functional portion. Separate segments comprising at least one in each case bar-shaped toothed segment and one shaft segment may be provided, which are aligned on a common longitudinal axis and are connected to one another at a joint. The method may involve providing a shaft raw material piece having a length that is a multiple of a shaft segment length, continuously grinding a part of a circumferential face of the shaft raw material piece across a multiple of the shaft segment length to produce a semi-finished shaft segment product, cutting to length a shaft segment from the semi-finished shaft segment product, providing a toothed segment, and joining the shaft segment to the toothed segment.

Abstract: A ceramic matrix composite (CMC) is formed by infiltrating a metal or alloy into a fiber preform in a reactor or furnace that is separated into multiple discrete temperature zones. The gradual cooling of the CMC is controlled, such that upon solidification, a narrow, planar, solidification front is created which allows the expanding metal or alloy to move into a hotter section of the fiber preform, opposed to the surface of the CMC. A discrete solidification front is established that moves through the ceramic matrix composite (CMC) as the composite cools.

Abstract: A steel composition, a reinforcement part of a vehicle using the steel composition and a method of manufacturing the reinforcement part using the steel composition are provided. In particular, the steel composition includes increased content of carbon components and the steel composition is processed by rapid heating and immediate quenching.

Abstract: A device for generating a microstructure with a structure gradient in an axisymmetric mechanical part having a hollow center and initially possessing a uniform structure with fine grains, the device including a first heater system defining a first shell for receiving the mechanical part and suitable for heating the outer periphery of the mechanical part to a first temperature higher than the solvus temperature. The device further includes a second heater system defining a second shell arranged inside the first shell and suitable for heating the inner periphery of the mechanical part to a second temperature lower than the solvus temperature, with the space between the first shell and the second shell defining a housing suitable for receiving the axisymmetric mechanical part having a hollow center.

Abstract: A process for joining fiber composite materials using self-piercing rivets. The process includes contacting first and second panels. The second panel is a fiber composite material. The process further includes elevating a temperature of only a fastening portion of the second panel. The process also includes placing the first and second panels on a die and joining the first and second panels with one or more rivets while the fastening portion is at an elevated temperature.

Abstract: Provided herein is a method of hot gas forming and heat treatment for a Ti2AlNb-based alloy hollow thin-walled component, which pertains to the technical field of plastic forming manufacture of thin-walled components made from difficult-to-deformation materials, more particularly, a forming method of Ti2AlNb-based alloy hollow thin-walled components is involved. The purpose of this invention is to solve the existing problems that Ti2AlNb-based alloy hollow thin-walled components are difficult to form, process steps are complex, and the shape and dimension precision is in contradiction with the control of the microstructure and properties. The method comprises the following steps: (1) hot gas forming to obtain hot gas formed tube components, and (2) controllable-cooling heat treatment to obtain Ti2AlNb-based alloy hollow thin-walled components.

Abstract: A forming apparatus that forms a metal pipe includes: a heating unit which heats a metal pipe material; a gas supply unit which supplies gas into a heated metal pipe material, thereby expanding the metal pipe material; a die which forms the metal pipe by bringing the expanded metal pipe material into contact with the die; a cooling unit which cools the metal pipe after the forming by a cooling medium; and a control unit which controls an operation of the die, the gas supply unit, and the cooling unit, wherein the control unit makes cooling of the metal pipe by the cooling medium be performed, by controlling an operation of the die such that the die is opened and controlling the cooling unit such that the cooling unit brings the cooling medium into contact with the metal pipe, subsequently to completion of forming by the die.

Abstract: A steel pipe for line pipe has a composition of, in mass %: C: 0.02 to 0.11%; Si: 0.05 to 1.0%; Mn: 0.30 to 2.5%; P: up to 0.030%; S: up to 0.006%; Cr: 0.05 to 0.36%; Mo: 0.02 to 0.33%; V: 0.02 to 0.20%; Ti: 0.001 to 0.010%; Al: 0.001 to 0.100%; N: up to 0.008%; Ca: 0.0005 to 0.0040%; and other elements and satisfies Cr+Mo+V?0.40, the chemical symbols in the equation substituted by the content of the corresponding element in mass %. The pipe contains tempered martensite and/or tempered bainite and further contains ferrite in at least one of a portion between a steel pipe outer surface and a depth of 1 mm from the outer surface, and a portion between a steel pipe inner surface and a depth of 1 mm from the inner surface.

Abstract: An induction heating coil includes a coil section configured to heat a treatment target by induction, a power supply section configured to supply power to the coil section, and a cooling medium passage that is arranged in the power supply section and the coil section, and is configured to supply a cooling medium to the coil section. The coil section, the power supply section, and the cooling medium passage are formed using a metal additive fabrication method.

Abstract: An induction heating coil includes a coil section configured to heat a treatment target by induction, a power supply section configured to supply power to the coil section, and a cooling medium passage that is arranged in the power supply section and the coil section, and is configured to supply a cooling medium to the coil section. The coil section, the power supply section, and the cooling medium passage are formed using a metal additive fabrication method.

Abstract: A traverse strut for use in a twist beam axle assembly is provided. The traverse strut extends along a length and presents a central section; a pair of end sections; and a pair of intermediate sections between the central section and the respective end sections. At least a portion of the central section has a first wall thickness, at least a portion of each end section has a second wall thickness that is greater than the first wall thickness and at least a portion of each intermediate section has a third wall thickness that is greater than the second wall thickness. Additionally, at least two of the central, intermediate and end sections is work hardened. The transverse strut has improved performance and lower weight as compared to other known transverse struts.

Abstract: A size hardening heat treatment process for steel parts of a plate, cylindrical or spherical shape and using low or specified hardenability steel compositions which are through surface heated and very rapidly quenched to produce case hardening of the part. A set of graphs are provided which depict the relationship between the depth of hardening and the dimension of the part for each of a series of critical, i.e., ideal diameter values which allow producing a depth of hardening of a particular part by a proper selection of the DI value of the part. The DI values are calculated by a formula which allows a range of DI values to be created by varying the components of the steel as set out in the formula. The formula also insures a fine grain size to be created by the process to prevent cracking by the very rapid quenching required. A list of elements allowed in the steel but limited by a % mass set out for each component.

Abstract: A deformation correcting device to correct a deformation occurring in a ring shaped article, which has been heated, while the heated ring shaped article is cooled, includes a support table, on which the ring shaped article in a heated condition is placed; a pair of receiving rolls; a press roll provided in opposition to the pair of the receiving rolls with the ring shaped article intervening therebetween; a press roll drive mechanism for driving the press roll between an advanced position, at which the press roll is urged against the outer peripheral surface of the ring shaped article, and a retracted position, at which the press roll is separated away from the outer peripheral surface of the ring shaped article; and a press roll rotating mechanism for rotating the press roll then urged against the ring shaped article by the press roll drive mechanism.

Abstract: The present invention relates to a method for heat treatment of a columnar work. In order to provide the method for heat treatment of a columnar work being able to attain a high productivity, a reduction of cost, and an improvement of quality, as compared with the prior art, the method for heat treatment of a columnar work of the present invention includes a quench-hardening step (S1) and a tempering step (S2) being carried out after the quench-hardening step (S1), the quench-hardening step (S1) includes a first quench-hardening step (S11) and a second quench-hardening step (S12) being carried out after the first quench-hardening step (S11), the entire region of the columnar work (3) from an outer circumferential surface (31f) to a core thereof (32), or a partial region thereof, is heated up to a temperature not lower than a transformation temperature Ac3, and then, the work is quench-hardened.

Abstract: In a method of making a tubular structural part for a motor vehicle, a metal plate is contoured and preformed in at least one shaping step into a tubular body. Subsequently, the tubular body is end-formed into the structural part by internal high-pressure application while free contact regions snugly bear upon one another. The structural part is at least partially heated and quenched in a holding tool acted upon with a coolant.

Abstract: The present invention relates to a process for producing a pipe, particularly for supplying fuel to an engine, comprising the steps of: prearranging a pipe made of stainless steel (1), executing a hot-pressing operation at at least one end (3) of the pipe (1); and subjecting the at least one end (3) of the pipe (1) to heat treatment, followed by cooling.

Abstract: A production method of a metal pipe which can suppress quenching defects is provided. In the production method of a metal pipe according an embodiment of the present invention bend of the metal pipe is straightened by a straightening machine 10. Next, both pipe end portions of the metal pipe whose bend has been straightened are cut off by a pipe cutting apparatus 20. Next, a plurality of the metal pipes whose both pipe end portions have been cut off are aligned in the axial direction thereof to be conveyed to a quenching apparatus 30, and the metal pipes are quenched by being cooled after being heated by induction heating.

Abstract: A method of quenching a ring shaped article includes heating the article to a quenching temperature; primarily cooling the article down to a deformation correction initiating temperature, which is higher than a martensitic transformation point; and secondarily cooling the article down to a temperature lower than the martensitic transformation point by, while a pair of receiving rolls are held in contact with an outer peripheral surface of the article for rolling motion about an axis of rotation parallel to a center of the article, pressing a press roll, rotatable about an axis of rotation parallel to the center of the article, against the outer peripheral surface of the article from one side of the article opposite to a point intermediate between the receiving rolls.

Abstract: A magnetic flux concentrator is used to control the end heating of a tubular material in an electric induction heat treatment process. The magnetic flux concentrator may consist of fixed elements, or a combination of fixed and moveable elements to accommodate end heating of tubular materials having different dimensions or material properties.

Abstract: A method for heat-treating a ring-shaped member includes the steps of: forming, by relatively rotating an coil along the circumferential direction of the formed body, an annular heated region in the formed body, the heated region having the steel austenitized therein; and simultaneously cooling a whole of the heated region to a temperature of not more than an Ms point. In the step of forming the heated region, the heating is performed to repeatedly change over for a plurality of times between a state in which each region of the rolling contact surface has a temperature exceeding a temperature of an A1 point and a state in which each region of the rolling contact surface has a temperature that is less than the temperature of the A1 point and that maintains a supercooled austenite state.

Abstract: A steel pipe with a wall thickness over 30 mm is subjected to heat treatment of quenching and tempering using a temperature range of at least not less than 750° C. during the heating stage, makes it possible to obtain a heavy-wall seamless steel pipe having excellent toughness by resulting grain refinement. Quenching is by performing water cooling after heating the steel pipe to a temperature in the range of not less than 900° C. to not more than 1000° C. by using, as a heating means, induction heating at a frequency of not more than 200 Hz. Tempering is performed at a temperature in the range of not less than 500° C. to not more than 750° C. Preferably, after the heating by induction heating, a soaking treatment is performed in the temperature range of not less than 900° C. to not more than 1000° C. for 10 minutes or less followed by water cooling.

Abstract: There is provided a steel pipe for fuel injection pipe that assures prolonged fatigue life and high reliability by securing a high critical internal pressure, at which fatigue fracture does not occur, while the material strength is high. A steel pipe for fuel injection pipe consisting of, by mass percent, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, the balance being Fe and impurities, the impurities containing Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, wherein the tensile strength thereof is not lower than 900 N/mm2, and the maximum diameter of a nonmetallic inclusion present during at least 20 ?m depth from the inner surface of the steel pipe is not larger than 20 ?m. Further, this steel pipe can contain one or more kinds of Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.

Abstract: A rolling-element bearing includes an inner ring made of steel and having an inner-ring raceway, an outer ring having an outer ring raceway, and ceramic rolling elements which roll on the inner-ring raceway and on the outer-ring raceway. The inner ring has been subjected to a heat treatment to harden it. The heat treatment is concluded with the performance of a final heat-treatment step at a predetermined temperature. In the inner ring, compressive residual stresses are formed in an outer layer by cold working in the region of the inner-ring raceway. The inner ring also has been subjected to a bluing treatment.

Abstract: A heavy wall and high strength seamless steel pipe having high sour resistance is provided. In particular, a quenching and tempering treatment is conducted to adjust the yield strength to be higher than 450 MPa and adjust the Vickers hardness HV5 that can be measured at an outermost side or an innermost side of the pipe under a 5 kgf load (test load: 49 N) to be 250 HV5 or less.

Abstract: A method and apparatus for annealing cylindrical cases for ammunition cartridges or other tubular casings is provided. In one embodiment, a case annealing apparatus is provided. The case annealing apparatus includes a base, a feeding device having a first end tapering to a second end that is coupled to the base, a rotatable feed wheel assembly disposed adjacent a second end of the feeding device, a linear slide mechanism disposed adjacent the rotatable feed wheel assembly defining a portion of a case receiving region, and a heating device disposed adjacent the case receiving region, the heating device operable to heat a portion of a case retained in the case receiving region.

Abstract: A method for producing a bearing ring of a rolling bearing includes the steps of: preparing a formed body constituted of hypereutectoid steel; forming an annular heated region heated to a temperature of at least an A1 point on the formed body by relatively rotating an induction heating member arranged to face part of an annular region for becoming a rolling contact surface of the bearing ring in the formed body to induction-heat the formed body along the circumferential direction of the annular region; and simultaneously cooling the whole of the heated region to a temperature of not more than an Ms point.

Abstract: An induction heat treatment method with which temperature control is enabled, condition setting is easy, and the quality of a treatment object can be stabilized includes: a data acquiring step of heating and quench-hardening a sample of the treatment object to thereby acquire process data; a storing step of storing the process data; a checking step of checking the power supply output transition data and the quenching timing data as to validity based on the temperature transition data stored in the storing step; and a mass production step of performing heat treatment of the treatment object in accordance with the power supply output transition data and the quenching timing data stored in the storing step and checked as to validity in the checking step.

Abstract: A treatment of a heater tube intended to be used in a pressurizer of the primary cooling system of a nuclear reactor. In particular, the heater tube comprises a heater housed in a substantially cylindrical sheath. The material of which this sheath is made is a work-hardened austenitic stainless steel. In particular, the external surface of the sheath is liable to undergo a stress corrosion during use of the heatertube. The method includes a heat treatment step, preferably using induction heating, in which the external surface of the sheath is heat-treated so as to recrystallize the material of the sheath at least on the surface thereof.

Abstract: Disclosed is a high-strength electric resistance welded steel pipe which is manufacture from a steel sheet containing, on mass basis, 0.2% to 0.4% C, 0.05% to 0.5% Si, 0.5% to 2.5% Mn, 0.025% or less P, 0.01% or less S, 0.01% to 0.15% or Al, 0.01% to 2% Cu, 0.05% to 2% Cr, 0.005% to 0.2% Ti, and 0.0002% to 0.005% B, with the remainder being iron and inevitable impurities. The steel pipe has a tensile strength of 1750 N/mm2 or more, a 0.1%-proof stress of 1320 N/mm2 or more, and a Charpy impact value at a testing temperature of minus 40° C. of 50 J/cm2 or more.

Abstract: A heat treatment method of heat-treating a steel tube provides the steel tube with satisfactory workability and high pressure resistance capable of coping with a recent increasing trend of pressure dealt with by a recent common rail type fuel injection system. A steel tube of a desired size is formed by drawing a material of a steel containing at least vanadium. The steel tube is processed for normalizing by holding the steel tube at high temperatures between 950 and 1000° C. for a predetermined time and slowly cooling the steel tube at a predetermined cooling rate. Then, the steel tube is processed for tempering by heating the steel tube at a temperature between 500 and 700° C. and cooling the steel tube to an ordinary temperature at an optional cooling rate.

Abstract: A steel pipe with a wall thickness over 30 mm is subjected to heat treatment of quenching and tempering using a temperature range of at least not less than 750° C. during the heating stage, makes it possible to obtain a heavy-wall seamless steel pipe having excellent toughness by resulting grain refinement. Quenching is by performing water cooling after heating the steel pipe to a temperature in the range of not less than 900° C. to not more than 1000° C. by using, as a heating means, induction heating at a frequency of not more than 200 Hz. Tempering is performed at a temperature in the range of not less than 500° C. to not more than 750° C. Preferably, after the heating by induction heating, a soaking treatment is performed in the temperature range of not less than 900° C. to not more than 1000° C. for 10 minutes or less followed by water cooling.

Abstract: A hollow shaft material is provided with, on an outer peripheral surface side thereof, for example, a movable induction heating coil wrapped therearound. While a high-frequency current with a predetermined frequency is caused to flow through the induction heating coil, the induction heating coil is axially moved to perform induction hardening of the hollow shaft material from the outer peripheral surface side. At this moment, the frequency of the high-frequency current caused to flow through the induction heating coil is set relatively low as to the small-diameter portions, which have a relatively small thickness, and the frequency of the high-frequency current caused to flow through the induction heating coil is set relatively high as to the large-diameter portion, which has a relatively small thickness.

Abstract: The present invention provides a method for induction hardening of a steel member having an outer ring portion and, more specifically, for induction hardening of an outer circumferential surface of the outer ring portion. The method uses two pressing members, each of which includes a flat basal surface and a projecting portion projecting therefrom. Each of the projecting portions has a cross-section in the shape of a perfect circle. Also, the projecting portions have, on the outer circumferences thereof, respective pressing surfaces. While gaps are maintained between axial end faces of the outer ring portion and the basal surfaces of the pressing members, the pressing members are pressed against the outer ring portion so that the pressing surfaces each abut against the inner circumference side of the outer ring portion. While a biasing force is applied to the pressing members, the induction hardening process is applied to the outer circumferential surface.

Abstract: A method of quenching a ring shaped article includes a heating step (S1) of heating the article (W) to a quenching temperature; a primary cooling step (S2) of cooling the article (W) down to a deformation correction initiating temperature, which is higher than a martensitic transformation point; and a secondary cooling step (S3) of cooling the article (W) down to a temperature lower than the martensitic transformation point by, while a pair of receiving rolls (3) are held in contact with an outer peripheral surface of the article (W) for rolling motion about an axis of rotation parallel to a center of the article (W), pressing a press roll (4), rotatable about an axis of rotation parallel to the center of the article (W), against the outer peripheral surface of the article (W) from one side of the article (W) opposite to a point intermediate between the receiving rolls (3).

Abstract: An apparatus (10) includes a low-carbon steel tube (24). The low-carbon steel tube (24) yields plastically more than about 5% before fracturing at temperatures down to about ?40° C. when stress is applied to the low-carbon steel tube sufficient to cause the low carbon steel tube to so yield.

Abstract: A high strength steel pipe for an airbag system has a steel composition comprising C: 0.05-0.20%, Si: 0.1-1.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, at least one of Ti and Mn satisfying (1) Ti?0.02% and (2) 0.4%?Mn+40Ti?1.2%, and a remainder of Fe. The composition may further include one or more of (i) at least one of Mo: 0.05-0.50%, Ni: 0.05-1.5%, V: 0.01-0.2%, and B: 0.0003-0.005%, (ii) at least one of Cu: 0.05-0.5% and Nb: 0.003-0.1%, and (iii) at least one of Ca: 0.0003-0.01%, Mg: 0.0003-0.01%, and REM: 0.0003-0.01%. The steel pipe can be manufactured by forming a pipe from the above-described steel composition to obtain prescribed dimensions, heating to at least the Ac1 transformation point and quenching, and then tempering at the Ac1 transformation point or below.

Abstract: A system and method is provided for tempering a glass container. The method includes the steps of pre-heating the glass container to a first predetermined temperature. The method also includes the steps of applying radio-frequency energy to the pre-heated glass container to heat the glass container to a second predetermined temperature and, after a predetermined amount of time, simultaneously cooling at least one surface of the heated glass container to a third predetermined temperature to treat the glass container. The method further includes the steps of, after a predetermined amount of time, quenching the treated glass container to a fourth predetermined temperature to produce a tempered glass container.

Abstract: A high frequency heat treatment method for a fine bottom-closed hole includes preparing a coil so as to be completely inserted into the fine bottom-closed hole, preparing a core for controlling a magnetic flux within the coil such that the core protrudes from upper and lower sides of the coil, heat-treating a target part of the fine bottom-closed hole under conditions of a heating time of 2˜3 seconds, an output power of 200˜300 kW, a quenching time of 3˜5 seconds, a positive electrode voltage of 4 ˜8 kV, and a positive electrode current of 2.0˜4.5 A, and quenching the heat-treated part of the fine bottom-closed hole with cooling nozzles fixed around the heat-treated part such that a sufficient amount of cooling water is injected uniformly over the whole heated part with a sufficient pressure via the cooling nozzles.

Abstract: Quenched layers are formed without irregularities on the inner circumferential surface of a track bushing having a small inside diameter or on the inner circumferential surfaces of two or more track bushings which are subjected to quenching in an overlapped condition. To introduce a cooling medium for cooling the inner circumferential surface of the track bushing, a guide tube having an outside diameter smaller than the inside diameter of the track bushing is disposed on the side of the inner circumferential surface and the cooling medium introduced by the guide tube is diverted by a diverting member having a spherical or similar curved surface, such that the cooling medium is allowed to flow in a direction substantially parallel with an axial direction of the track bushing 1 within a space defined by the outer circumferential surface of the guide tube and the inner circumferential surface of the track bushing, thereby performing laminar flow cooling.

Abstract: The present invention relates to a process for producing a pipe, particularly for supplying fuel to an engine, comprising the steps of: prearranging a pipe made of stainless steel (1), executing a hot-pressing operation at at least one end (3) of the pipe (1); and subjecting the at least one end (3) of the pipe (1) to heat treatment, followed by cooling.

Abstract: A method for the production of mechanically highly stressed machinery components, with at least one pass-through opening, especially suction roll sleeves on paper machines, includes the material characteristics of the machinery component being altered with regard to an increase in the resistance against vibratory fissure corrosion on the machinery component in the localized area of the pass-through opening. A roll sleeve produced according to this method is also provided.

Abstract: An induction heat treatment method with which temperature control is enabled, condition setting is easy, and the quality of a treatment object can be stabilized includes: a data acquiring step of heating and quench-hardening a sample of the treatment object to thereby acquire process data; a storing step of storing the process data; a checking step of checking the power supply output transition data and the quenching timing data as to validity based on the temperature transition data stored in the storing step; and a mass production step of performing heat treatment of the treatment object in accordance with the power supply output transition data and the quenching timing data stored in the storing step and checked as to validity in the checking step.

Abstract: A method of forming a dual chamber seamless tube (64) includes providing a slug of steel (56) and cold working a first end (70) of the slug (56) to form a first chamber (114) and cold working a second end (72) of the slug (56) to form a second chamber (116). The first and second chambers (114 and 116) are axially aligned and separated by a wall portion (126) of the tube (64).

Abstract: Disclosed is an apparatus and method for forming thermal fatigue cracks in a test piece for performance demonstration of nondestructive testing. The apparatus for forming thermal fatigue cracks includes a heating unit, having a conductive member attached around the outer surface of a pipe test piece and an induction heating coil disposed adjacent to the conductive member; a cooling unit, having a cooling water pump for forcibly supplying cooling water to the inner surface of the pipe test piece from a cooling water storage source and a cooling water hose; and a control unit for controlling operation of the heating unit and the cooling unit. Accordingly, thermal fatigue cracks similar to actual thermal fatigue cracks occurring during the operation of nuclear power plants or processing industry equipment are formed in a test piece, thereby assuring effective performance demonstration of nondestructive testing.

Abstract: A steel material of 85 to 95 HRB exhibiting a ratio of area occupied by ferrite of 30% or higher, which steel material comprises given amounts of C, Si, Mn, S, Ti, Cr, Al and B and the balance of iron and unavoidable impurities, is subjected to induction hardening. After the hardening, the surface of the steel material exhibits an Hv value of 640 to 730. When t refers to the effective hardening depth, namely, the distance from the surface to a region exhibiting an Hv value of 392 and r refers to the radius of the steel material, the hardened layer ratio, t/r, is 0.4 or higher.

Abstract: The present invention provides a method for induction hardening of a steel member having an outer ring portion and, more specifically, for induction hardening of an outer circumferential surface of the outer ring portion. The method uses two pressing members, each of which includes a flat basal surface and a projecting portion projecting therefrom. Each of the projecting portions has a cross-section in the shape of a perfect circle. Also, the projecting portions have, on the outer circumferences thereof, respective pressing surfaces. While gaps are maintained between axial end faces of the outer ring portion and the basal surfaces of the pressing members, the pressing members are pressed against the outer ring portion so that the pressing surfaces each abut against the inner circumference side of the outer ring portion. While a biasing force is applied to the pressing members, the induction hardening process is applied to the outer circumferential surface.

Abstract: Provided is a method of manufacturing a hollow power transmission shaft, which makes it possible to ensure stable quality even when there is a difference in wall thickness or hardening ratio along an axial direction thereof. A hollow shaft material (1?) is provided with, on an outer peripheral surface (1g) side thereof, for example, a movable induction heating coil (5) wrapped therearound. While a high-frequency current with a predetermined frequency is caused to flow through the induction heating coil (5), the induction heating coil (5) is axially moved to perform induction hardening of the hollow shaft material (1?) from the outer peripheral surface (1g) side.